1) No opinion, I dont have any of those psu.

2) Noise wise there SHOULD be no difference between A-PFC and P-PFC (and even non-PFC). However, as per somebody else's excellent tag elsewhere, "In theory there is no difference between theory and practice. In practice there is." See also:
Active PFC calrification, MikeC or anyone can chip in...
Active v.s. Passive PFC?
PSU issues

3) Well, you have to mod every psu you buy. Whether you want to limit yourself to a fan swap ...
Actually it probably depends on your skills/attitude to modding and requirements for warranty etc. If you are re-selling or desire to maintain the warranty then do not swap: rather start with a Seasonic/Nexus and don't do anything. If you belong to the part of the population that starts the mod before you get the kit home for the first time, then yes, even a Seasonic or Nexus may benefit from a 'flo. (See also Mike's conclusion in the Seasonic review.

4) My main opinion is the SLK-800 is plenty for me: the 900 is no doubt 'better' but not sure it is worth the premium. You may want to consider 800A/900A - it seems the hole mounts are vanishing from socket-A boards (since AMD removed it from their spec this is unsurprising!)
And personally I would mod any psu before buying new, especially if you have fans & tin snips available.

I own both a Seasonic. and the PSU you've got. And oh yes, you will notice a difference. You won't realise how loud what you have is until it's gone.

But before you replace it I'd suggest modding it. I've been running my Enermax, modded by removing the 92mm altogether and swapping the 80mm for a 7 volted L1A, for over a year without a hiccup. With these mods it's nearly as the Seasonic. If you're up to tinkering it may be worth modding it before you swap it.

Active PFC is better than Passive, but it's not going to make a difference in the noise. Only in your electric bill.

The SLK-900 is slightly better than the 800. But it's also more expensive, heavier, and since it's bigger you may have clearance issues with it on your mobo. The through-bolts are a good idea if your board has the holes, but realise that buying the "A" variety of SLK may mean that you won't be able to reuse it if you replce the mobo down the line.

Case fans: Do either all exhaust or all intake, doing one of each is a waste. You may want to think about keeping that side opening. On my case I've got a side intake that I use with an 80mm L1A ducted to an SLK-800. By drawing in cool outside air you can reduce the amount of airflow you need on the CPU. I run an XP2100 OC'd to 2.0Ghz, with the duct fan at 7v, and my temps stay about 42°C max.


Oh, and once you do all this you'll realise how loud that 9500 is. (I've got one of those too. Passively cooled by a Zalman HP-80)

the 92mm fan is the one on the inside of the case, on the bottom of the psu

I also removed the 92mm fan, covered up the hole with some cardboard and tape, put a 80mm panaflo L1A where the stock rear exhaust fan was in the psu, but I connected the panaflo to the thermally controlled fan connector on the psu, where the 92mm was connected before.. (no soldering required, just modify the panaflo connector a bit, or pull off the white connector from the psu pcb)

The difference after this, is like night and day, the enermax 80mm was LOUD

I have the FC model, where the 80mm fan is controlled by the motherboard, so the 80mm fan was connected to my motherboard..

And judging by other reviews and users experiences, in the other enermax models, the 80mm fan seems to speed up to full speed after a few minutes, while the 92mm fan is fed a low voltage...

the 80mm panaflo connected to where the stock 92mm fan was, is being fed much less than 12v, I can really notice the difference in airflow compared to my case exhaust fan which is at 12v...

The air exiting the psu however, is still cooler than the air exiting from the case exhaust fan..

Case airflow:

Yes, the normal flow is; in the lower front and out the back top. But you don't need an intake fan to make the air flow that way. If you have the air being pushed out the back it has to come in somewhere, right? The air will come in wherever there are openings, namely the big holes in the lower front where you could put fans.

Well I'm talking about having both an intake, and an exhaust being useless. I think you should have either/or, but not both.


Now having both will help, if....

1. You need it to blow on something specific, like a HDD.
2. Your case has lots of holes in bad places. Like a big hole in the side up at the top that would let air in, bypassing the rest of the case. (Duct tape would fix #2)

Other than that, nope. Well, at least not enough to be worth doubling the amount of fan noise.


Now just to cut any detractors off at the pass let me add:

In theory....only having exhaust fans results in lower air pressure inside the case, which reduces the heat transfer from the heatsinks to the air. And the lower air pressure results in more dust buildup inside the case.

But....At the airflow rates we're talking about the air pressure drop is tiny. (In fact if anyone can even find a measurable difference in air pressure quoted reliably anywhere, I'll send you a cookie) And the change in thermal conductivity due to this tiny change in pressure is even tinier yet. (In fact I'd bet the increase in case temp due to the extra intake would offset the drop) Axial fans simply cannot produce the kind of a pressure gradiant that would be required for these effects to become important.

And dust is not a good enough reason, for me at least, to double the amount of noise being produced by my case fans. I think most of the dust reduction from intake fans occurs by the act of the fan blades themselves actually catching the dust. Use a filter, or just buy a can of compressed air and give the inside a shot every month or two.


OK, that's enough CYA for one post.

Only place I know people have gotten HDD grommets are mcmastercarr.com I don't know the model #'s though.

I got my 800U at SVC< but the price there right now is not the best. Try all the regulars:

Case-mod.com
directron.com
frozencpu.com
heatsinkfactory.com
svc.com
newegg.com

Be sure to factor in shipping.

Ralf comes through as usual. Quoted from this thread:

A very simple and more effective mod is to place the whole hard disk bottom side down onto a piece of foam at the bottom of your case. This will raise the temps of the HDD a little though so check temps to see if you do or do not need a front intake fan. Rubber grommets are ok but vibrations are still carried from the screws to the drive cage. I have tried both methods and the foam is far more effective.

I agree with Rusty's points, I don't have any front intake fans either only exhausts.

Silicon Acoustics has these also...

McMaster-Carr has the isolators and grommets, but don't seem to have the mounting screws. At least, I couldn't find them.

The ones that comes with the Antec Sonata case is designed so that you won't over-tighten and destroy the HDD.

Here's a picture (from www.earsc.com).



I suppose you can always use regular machine screws of the right length, with a washer if necessary. It's just that this one looks so much nicer...